<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .main::after {
            content: "";
            clear: both;
        }

        .main>div {
            float: left;
            height: 250px;
            background-color: #b4a078;
            color: white;
        }

        .main .left,
        .main .right {
            /* 左右两栏固定宽度 */
            width: 119px;
        }

        .main .center {
            background-color: aquamarine;
            width: calc(100% - 119px * 2);
        }
    </style>
</head>

<body>
    <div class="main">
        <div class="left"></div>
        <div class="center"></div>
        <div class="right"></div>
    </div>
</body>

</html>